Funding for this research was provided by:
the National Natural Science Foundation of China (31671656)
National High Technology Research and Development Program of China (No. 2014AA10A600)
National Research Foundation for the Doctoral Program of Higher Education of China (No. 20120146110013)
Article History
Received: 8 May 2019
Accepted: 24 September 2019
First Online: 1 November 2019
Ethics approval and consent to participate
: Not applicable.
: Not applicable.
: The authors declare that they have no competing interests.